mx31pdk: Remove dram_init_banksize()

As only one RAM bank is used we can rely on the code from arch/arm/lib/board.c

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

board/freescale/mx31pdk/mx31pdk.c

@@ -47,12 +47,6 @@ int dram_init(void)
 	return 0;
 }
 
-void dram_init_banksize(void)
-{
-	gd->bd->bi_dram[0].start = PHYS_SDRAM_1;
-	gd->bd->bi_dram[0].size = PHYS_SDRAM_1_SIZE;
-}
-
 int board_early_init_f(void)
 {
 	/* CS5: CPLD incl. network controller */